Effects of thrombolysis on vectorcardiographic indices of ventricular repolarization: correlation with ST-segment
Polychronis Dilaveris1, Aristides Anastasopoulos, Aristides Androulakis
11st University Department of Cardiology, Hippokration Hospital, 115 27 Athens, Greece. hrodil@yahoo.com
Insights
Thrombolysis significantly altered vectorcardiographic (VCG) measures of ventricular repolarization in acute myocardial infarction patients. However, ST-segment resolution proved a more reliable indicator of coronary artery patency post-thrombolysis.
Area of Science:
- Cardiology
- Medical Imaging
- Physiology
Background:
- Acute myocardial infarction (AMI) requires prompt reperfusion therapy.
- Thrombolysis is a key treatment for AMI, aiming to restore coronary blood flow.
- Assessing treatment efficacy is crucial for patient outcomes.
Purpose of the Study:
- To evaluate the impact of thrombolysis on vectorcardiographic (VCG) parameters of ventricular repolarization.
- To correlate changes in VCG descriptors with ST-segment resolution and coronary artery patency.
- To determine the utility of VCG descriptors as markers of thrombolysis efficacy.
Main Methods:
- Seventy AMI patients undergoing thrombolysis had digital 12-lead ECGs recorded before and 3 hours after treatment.
- Vectorcardiographic descriptors, including spatial T amplitude and spatial QRS-T angle, were analyzed.
- Coronary angiography was performed to assess infarct-related artery patency.
Main Results:
- Spatial T amplitude significantly decreased post-thrombolysis in patients with patent coronary arteries (P<.0001).
- Spatial QRS-T angle also showed a significant reduction in patent artery groups (P=.019).
- ST-segment resolution (≥60%) and spatial T amplitude reduction (25%) identified coronary patency with high sensitivity and specificity.
Conclusions:
- Thrombolysis significantly affects VCG descriptors of ventricular repolarization in AMI.
- VCG descriptors show moderate efficacy in marking thrombolysis success compared to ST-segment resolution.
- ST-segment resolution is a more robust indicator of infarct-related artery patency post-thrombolysis.
Abstract:
To investigate the effects of thrombolysis on vectorcardiographic (VCG) descriptors of ventricular repolarization in association with ST-segment resolution, 70 consecutively recruited patients with acute myocardial infarction underwent digital 12-lead electrocardiograms (ECGs) before and at 3 hours after thrombolysis. The alterations in the VCG descriptors spatial T amplitude and spatial QRS-T angle from the pre- to the post-thrombolysis ECG, as well as the ST-segment resolution, were calculated. Angiography revealed patency of the infarct-related coronary artery after thrombolysis in 52 (74%) patients (group A) and occlusion in 18 (26%) (group B). The spatial T amplitude was highly significantly reduced after thrombolysis in group A (P<.0001), but only marginally reduced in group B (P=.016). The spatial QRS-T angle was also significantly, although only marginally, reduced after thrombolysis in group A (P=.019), whereas it was not changed after thrombolysis in group B (P=.868). An ST-segment resolution of 60% and a 25% reduction in the spatial T amplitude after thrombolysis were able to identify patency of the infarct-related coronary artery with sensitivities of 90% and 77% and specificities of 94% and 74%, respectively. Both VCG descriptors were significantly affected by thrombolysis in patients with acute myocardial infarction, but constituted only moderate markers of thrombolysis efficacy, as evidenced by the presence of patency in the infarct-related coronary artery, compared with the ST-segment resolution.
